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%I #17 Aug 05 2024 14:23:05
%S 7,6,2,1,0,7,4,4,8,1,8,4,9,4,4,8,4,6,8,4,8,7,1,8,4,9,1,8,8,5,0,9,2,8,
%T 4,9,2,0,0,9,0,5,9,6,8,7,9,9,4,8,7,7,4,1,3,3,8,9,2,7,6,0,3,6,8,4,3,5,
%U 4,6,2,2,3,7,4,8,7,9,7,1,2,6,0,1,2,1,2,7,3,2,1,0,0,4,3,9,0,6,7,1,4,3,6,7,8
%N Decimal expansion of Sum_{k>=2} (arctanh(1/k) - 1/k).
%H Michael Ian Shamos, <a href="https://citeseerx.ist.psu.edu/pdf/ae33a269baba5e8b1038e719fb3209e8a00abec5">Shamos's Catalog of the Real Numbers</a>, 2011, pp. 126-127.
%F Equals Sum_{k>=1} (zeta(2*k+1)-1)/(2*k+1).
%F Equals 1 - gamma - log(2)/2, where gamma is Euler's constant (A001620).
%F Equals Sum_{k>=2} ((1/2)*log((k+1)/(k-1)) - 1/k).
%F Equals 2 * Integral_{x>=0} x * exp(-x) * log(x) * sin(x) dx.
%e 0.07621074481849448468487184918850928492009059687994877413...
%t RealDigits[1 - EulerGamma - Log[2]/2, 10, 100][[1]]
%Y Cf. A001620, A002162, A016655, A239097, A352619, A355922.
%K nonn,cons
%O -1,1
%A _Amiram Eldar_, Jul 21 2022